In a meat processing plant, various different processing operations are carried on at various different locations. For example animals are killed in one location, washed and cleaned in another and may be dressed in a third, and may be chilled either as whole carcasses, or as dressed meat sections, or may be cooked or smoked and may be packaged.
In the majority of meat processing plants, the products, e.g. meat sections and the like, and carcasses, are carried on a single conveyor, being hung by gambrels, chains, or hangers from trolleys running on the conveyor. For various reasons, it may considerably facilitate the operation if it is possible to transfer the products from one conveyor to another for a specific processing operation. In this way it is possible to provide a conveyor designed specifically for that processing location, which does not extend through the rest of the plant. A transfer station is provided where products can be loaded onto the processign chamber conveyer at the entrance to the processing chamber, and dropped off the conveyor for transfer to another location in the plant, at the exit from the processing chamber.
Advantageously this will be carried out without disturbing the attachment of the product to the gambrel, chain, or hanger.
For example, in the butchering of hogs, it is advantageous if the hog carcass is chilled, after hanging and dressing, and prior to further processing. A rapid chilling of the carcass results in better quality meat and less shrinkage. Accordingly it has become the practice to convey carcasses from the dressing area or kill floor through a chilling room, so as to produce a predetermined dwell time in the chilling room, and then to convey them for further processing in other facilities.
In the great majority of slaughter houses, the conveying system for conveying carcasses consists of a single carrier rail, and wheeled carriers riding freely on the carrier rail. Hooks or gambrels are used to attach the carcasses to the carriers. Typically this carrier rail is a plain bar of steel about 12.0 mm wide. The carriers employ a single wheel, grooved to receive the rail. The wheels are mounted in a yoke-like frame and a lubricant or grease is used to lubricate the wheel bearings. In order to move the carriers along the carrier rail, a conveyor rail is mounted usually above the carrier rail. On the conveyor rail, there are a series of trolleys linked together by a continuous chain. Normally there will be some form of fingers or pushers at spaced intervals along the chain, usually one to each of the conveyor trolleys, for pushing the carriers. One particularly adaptable form of conveyor rail is an I-beam, with conveyor trolleys runnig on the I-beam, and connected by a chain.
In the past it has been the practice to use this type of carrier rail, and conveyor rail, to extend completely through the kill floor and other locations and through the chill room, for conveying the carcasses into, and through and out of the various processing locations or chambers. Certain difficulties have however been experienced using this system. In the chilling chamber in order to procure an adequate degree of chilling, it is desirable to maintain a low temperature, accompanied by rapid air circulation. However, in such a reduced temperature the lubricant or grease used to lubricate the carrier wheel bearings solidifies. When this happens the wheels freeze on their axles and will no longer rotate. The carrier are then simply dragged along with their wheels skidding on the carrier rail throughout the length of the chill room. This, in turn, causes rapid wear of the carrier rail and carriers, and also puts an excessive strain on the conveyor chain and drive motor.
One solution to the problem has been to use a low-temperature lubricant for the carrier wheel bearings. While this overcomes the problem in the chill room itself, it also leads to other problems. Thus when the carriers are not in the chill room, they are located either in the kill floor or some other facility, where the air may be at plant ambient temperature in the region of 68 to 85 degrees Farenheit. At these temperatures the low-temperature lubricants become liquid, and as the carrier wheels rotate, the lubricant drips out and soils the carcass. This then requires a further washing or meat trimming step, and some of such lubricants are difficult to remove in a satisfactory manner.
Other problems may arise in other locations or processing chambers in such plants, where products such as carcasses, meat sections, and cooked or smoked meats and sausage, are processed.
Accordingly, it is desirable to provide for a form of conveyor in the processing chamber which overcomes problems such as lubrication, without interfering with the carrier system as used throughout the remainder of the plant, and without involving the handling of the products.